Chosen Solution
Hello. I have a question. There was a boot loop problem on this iPhone. I made iTunes restore to factory default using DFU mode. Unfortunately I can not activate the iPhone now. When I connect an iPhone to iTunes, it wants a SIM card, but even after inserting a SIM card it fails to activate. Does anyone know where the problem is? Thank you for your answear. Simon
The boot loop was probably caused by a logic board failure. Once you restored it, the same failure is impeding your device from activating. That gives us a clue that the issue could have to do with the cellular subsystem (which is used in activation). The iPhone 6 series is well known to have Baseband IC failures due to some weak traces on the logic board. I believe you will have to have this device looked at by a shop that does micro-soldering repairs.
